1. Field of the Invention
The present invention relates to a calibrated mechanical winch, and more particularly, but not by way of limitation, to a calibrated mechanical winch, constructed at least in part of a non-electrically conductive material, that allows users to ascertain a general level of tension applied to a wire, cable, rope, or other tensionable element.
2. History of the Related Art
Many devices have been used for tensioning cables, wires, and other tensionable elements. Electrically-charged objects such as, for example, power-transmission wires, require specialized equipment for safe tensioning.
Equipment utilized for tensioning of metallic objects such as, for example electrical transmission wires, often requires specialized instrumentation for determining a precise magnitude of tension applied. For example, objects constructed of metallic materials have a known thermal coefficient of expansion. Such objects expand and contract as ambient temperature rises or falls. If, for example, a metallic wire is installed during summer at a select tension, when ambient temperature drops in autumn and winter, the metallic wire contracts, thereby increasing a tensile load on the metallic wire. Such an increased load may result in the metallic wire breaking. For this reason, it is important to determine how much tension, relative to the ambient temperature, has been placed upon a wire, cable, rope, or other tensionable element during tensioning.
Tensioning of electrical-transmission wires is not the only application where cables, wires, ropes, and other tensionable elements require stretching. When erecting vertical structures, such as radio or television antenna towers, wire stays or the like are often used. Tensioning devices must be incorporated in such applications in order to avoid risk of property damage and personal injury should a magnitude of tension applied to the wire stay fall outside of an engineering specification.
In particular, equipment utilized for tensioning electrically-charged objects must be constructed of electrically non-conductive materials. Use of electrically non-conductive materials allows mechanical interaction with electrically-charged objects while protecting the user from electrical shock.